//I am never going to move home again.//
Now there are 8 words that I've used on more than one occasion (NEVER AGAIN, I SCREAM). I hope, for the sake of your own sanity, that is the case. My future father-in-law's attitude to us moving was enough to make me never want to move again. Where we are now is where we are staying to my clogs are popped.
Good luck with getting moved into your new house. As far as an answer to your question, I don't think I can add anything that hasn't already been said by everyone else. I think I'd have to agree with Anne, if he has been recommended to you by someone you know (even better if you've seen the work first-hand), go with that person and pay on completion and after you've inspected his work. He may want you to pay for the materials beforehand (either in full, or a part payment), however I'm sure you already know all that.
Good luck and don't forget my invite when you've got settled in. I'll bring some chocolate coated/covered gifts with me. ;)